Fluid recirculation system for use in vapor phase particle production system

ABSTRACT

A method of and system for recirculating a fluid in a particle production system. A reactor produces a reactive particle-gas mixture. A quench chamber mixes a conditioning fluid with the reactive particle-gas mixture, producing a cooled particle-gas mixture that comprises a plurality of precursor material particles and an output fluid. A filter element filters the output fluid, producing a filtered output. A temperature control module controls the temperature of the filtered output, producing a temperature-controlled, filtered output. A content ratio control module modulates the content of the temperature-controlled, filtered output, thereby producing a content-controlled, temperature-controlled, filtered output. A channeling element supplies the content-controlled, temperature-controlled, filtered output to the quench chamber, wherein the content-controlled, filtered output is provided to the quench chamber as the conditioning fluid to be used in cooling the reactive particle-gas mixture.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S Provisional ApplicationSer. No. 60/928,946, filed May. 11, 2007, entitled “MATERIAL PRODUCTIONSYSTEM AND METHOD,” which is hereby incorporated by reference as if setforth herein. The co-pending U.S. patent application Ser. No.11/110,341, filed on Apr. 10, 2005, entitled, “HIGH THROUGHPUT DISCOVERYOF MATERIALS THROUGH VAPOR PHASE SYNTHESIS” is incorporated byreference.

FIELD OF THE INVENTION

The present invention relates generally to the field of particleproduction. More specifically, the present invention relates to systemsand methods for recirculating fluid used within a vapor phase particleproduction system.

BACKGROUND OF THE INVENTION

Many vapor phase particle production systems produce mixtures ofparticles and fluid. Typically, these mixtures are high in temperatureand thus reactive. In some systems, these mixtures are quenched viaintroduction of a conditioning fluid. The conditioning fluid acts tocool the mixture and promote particle formation, and often acts as acarrier for the particles. Typically, particles are sampled or collectedfrom the mixture following introduction of the conditioning fluid. Then,the conditioning fluid is vented to the ambient, or otherwise disposed.This disposal occurs because typical particle production systems requirehigh purity gases as conditioning fluids. In many cases, the purity mustbe on the order of 99.9999% purity. The unit cost of particles producedusing these methods is inflated by the need to use fresh fluid for eachproduction run.

What is needed in the art is a way to reduce the costs associated with avapor phase particle production system, while at the same timemaintaining a high purity level for the system.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a particle production systemcomprises a particle production core and a fluid recirculation systemfluidly coupled to the particle production core. The production core isconfigured to produce a reactive particle-gas mixture from a precursormaterial and a working gas, and to quench the reactive particle-gasmixture using a conditioning fluid, thereby producing a cooledparticle-gas mixture. The cooled particle-gas mixture comprises aplurality of precursor material particles and an output fluid. Theoutput fluid includes the conditioning fluid. The fluid recirculationsystem is configured to receive the cooled particle-gas mixture from theparticle production core, and to remove the plurality of precursormaterial particles from the cooled particle-gas mixture, therebyproducing a filtered output that includes the output fluid. The fluidrecirculation system is also configured to modulate a content ratio ofthe filtered output, thereby producing a content-controlled, filteredoutput, wherein the filtered output comprises a distinct primary fluidand a distinct secondary fluid, and the content ratio is the ratio ofthe primary fluid to the secondary fluid. The fluid recirculation systemis further configured to channel the content-controlled, filtered outputto the particle production core, wherein the content-controlled,filtered output is provided to the particle production core as theconditioning fluid to be used in quenching the reactive particle-gasmixture.

In a preferred embodiment, the particle production core comprises aparticle production reactor and a quench chamber fluidly coupled to theparticle production reactor. The particle production reactor isconfigured to receive the precursor material and the working gas, toenergize the working gas to form a plasma, and to apply the plasma tothe precursor material, thereby producing the reactive particle-gasmixture. The quench chamber is configured to receive the reactiveparticle-gas mixture from the particle production reactor, to receivethe content-controlled, filtered output from the recirculation system asthe conditioning fluid, and to mix the received conditioning fluid withthe reactive particle-gas mixture, thereby producing the cooledparticle-gas mixture.

In some embodiments, the fluid recirculation system is furtherconfigured to control the temperature of the filtered output prior tomodulation of the content ratio.

Furthermore, in some embodiments, the fluid recirculation system isfurther configured to sense the ratio between the primary fluid and thesecondary fluid, and to modulate the content ratio of the filteredoutput by adjusting the amount of either the primary fluid or thesecondary fluid in the content-controlled, filtered output based on thesensed ratio.

In another aspect of the present invention, a particle production systemcomprises a particle production reactor and a quench chamber having afluid inlet, a reactive mixture inlet fluidly coupled to the particleproduction reactor, and a cooled mixture outlet. The particle productionsystem also comprises a filter element fluidly coupled to the cooledmixture outlet, a temperature control module fluidly coupled to thefilter element, a content ratio control module fluidly coupled to thetemperature control module, and a channeling element fluidly couplingthe content ratio control module to the fluid inlet of the quenchchamber.

The particle production reactor is configured to produce a reactiveparticle-gas mixture from a precursor material and a working gas. Thequench chamber is configured to receive a conditioning fluid at thefluid inlet, to receive the reactive particle-gas mixture mix fluid fromthe particle production reactor at the reactive mixture inlet, and tomix the conditioning fluid with the reactive particle-gas mixture toproduce a cooled particle-gas mixture. The cooled particle-gas mixturecomprises a plurality of precursor material particles and an outputfluid, the output fluid including the conditioning fluid. The filterelement is configured to receive and filter the output fluid from thequench chamber to produce a filtered output. The temperature controlmodule is configured to control the temperature of the filtered outputto produce a temperature-controlled, filtered output. The content ratiocontrol module is configured to modulate a content ratio of thetemperature-controlled, filtered output, thereby producing acontent-controlled, temperature-controlled, filtered output, wherein thetemperature-controlled, filtered output comprises a distinct primaryfluid and a distinct secondary fluid, and the content ratio is the ratioof the primary fluid to the secondary fluid. Finally, the channelingelement is configured to supply the content-controlled,temperature-controlled, filtered output to the fluid inlet of the quenchchamber, wherein the content-controlled, filtered output is provided tothe quench chamber as the conditioning fluid to be used in quenching thereactive particle-gas mixture.

In a preferred embodiment, the particle production reactor is configuredto energize the working gas to form a plasma, and to apply the plasma tothe precursor material, thereby producing the reactive particle-gasmixture.

In some embodiments, the system also comprises a suction generatorconfigured to generate a suction force at the cooled mixture outlet ofthe quench chamber to draw the output fluid from the quench chamber.

In some embodiments, the filter element is configured to remove theplurality of precursor material particles from the output fluid toproduce the filtered output. Furthermore, the filter element preferablycomprises a high efficiency particulate air (HEPA) filter.

In some embodiments, a pressure relief module is fluidly coupled betweenthe filter element and the temperature control module. This pressurerelief module is configured to reduce the pressure of the filteredoutput if the pressure exceeds a predetermined threshold.

In some embodiments, the temperature control module comprises a heatexchanger. It is also contemplated that other means for adjusting fluidtemperature can be employed.

In a preferred embodiment, the content ratio control module comprises asensor and a micro-controller communicatively connected to the sensor.The sensor is configured to sense the content ratio of thetemperature-controlled, filtered output, and to produce a signalrepresenting the sensed content ratio. The micro-controller isconfigured to receive the signal from the sensor and modulate thecontent ratio of the content-controlled, temperature-controlled,filtered output that is to be supplied to the fluid inlet of the quenchchamber. This modulation is based on the received signal.

In some embodiments, the content ratio control module can furthercomprise a buffer reservoir fluidly coupled to the temperature controlmodule and to the sensor. The buffer reservoir is configured to receivethe temperature-controlled, filtered output from the temperature controlmodule and to temporarily store the temperature-controlled, filteredoutput before the content ratio of the temperature-controlled, filteredoutput is modulated. The content ratio control module can also comprisea fluid relief valve fluidly coupled between the buffer reservoir andthe ambient atmosphere. This fluid relief valve is configured to ventthe secondary fluid from the buffer reservoir to the ambient atmosphere.

Furthermore, the content ratio control module can comprise a secondaryfluid supply reservoir that stores a supply of the secondary fluid andis communicatively connected to the micro-controller. This secondaryfluid supply reservoir is configured to selectively add a portion of thesecondary fluid from the secondary fluid supply reservoir into thetemperature-controlled, filtered output in response to a signal from themicro-controller, thereby producing the content-controlled,temperature-controlled, filtered output.

The content ratio control module can additionally or alternativelycomprise a primary fluid supply reservoir that stores a supply of theprimary fluid and is communicatively connected to the micro-controller.The primary fluid supply reservoir is configured to selectively add aportion of the primary fluid from the primary fluid supply reservoirinto the temperature-controlled, filtered output in response to a signalfrom the micro-controller, thereby producing the content-controlled,temperature-controlled, filtered output.

In addition to these systems, the present invention also includesmethods of recirculating fluid within these systems, involving theoperations discussed both above and below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of one embodiment of a fluidrecirculation system integrated into a particle production system inaccordance with the principles of the present invention.

FIG. 2 is a schematic illustration of one embodiment of the particleproduction system of FIG. 1 with a more detailed embodiment of thecontent ratio control module in accordance with the principles of thepresent invention.

FIG. 3A is a schematic illustration of one embodiment of a content ratiocontrol module in accordance with the principles of the presentinvention.

FIG. 3B is a schematic illustration of another embodiment of a contentratio control module in accordance with the principles of the presentinvention.

FIG. 4 is a flow chart illustrating one embodiment of a method ofrecirculating a fluid in a particle production system in accordance withthe principles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The description below concerns several embodiments of the invention. Thediscussion references the illustrated preferred embodiment. However, thescope of the present invention is not limited to either the illustratedembodiment, nor is it limited to those discussed. To the contrary, thescope should be interpreted as broadly as possible based on the languageof the Claims section of this document.

In the following description, numerous details and alternatives are setforth for purpose of explanation. However, one of ordinary skill in theart will realize that the invention can be practiced without the use ofthese specific details. In other instances, well-known structures anddevices are shown in block diagram form in order not to obscure thedescription of the invention with unnecessary detail.

This disclosure refers to both particles and powders. These two termsare equivalent, except for the caveat that a singular “powder” refers toa collection of particles. The present invention may apply to a widevariety of powders and particles.

The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings. Tofacilitate this description, like reference numerals designate likeelements.

FIG. 1 illustrates one embodiment of a fluid recirculation systemintegrated into a particle production system 100 in accordance with theprinciples of the present invention. The particle production system 100includes a particle production core 120, which takes various materialinputs, including both working and conditioning fluids as well asparticle precursors, and produces a particle-gas mixture. The two maincomponents of the particle production core 120 are a particle productionreactor 122, configured to produce a reactive particle-gas mixture froma precursor material and a working gas, and a quench chamber 124,configured to quench the reactive particle-gas mixture using aconditioning fluid.

In general, vapor phase particle production means are preferred forproducing the particle-gas mixture in the particle production core 120.Most preferably, the embodiments of the present invention use particleproduction systems similar to those disclosed in U.S. patent applicationSer. No. 11/110,341, filed on Apr. 19, 2005 and entitled, “HIGHTHROUGHPUT DISCOVERY OF MATERIALS THROUGH VAPOR PHASE SYNTHESIS”, whichis currently published as U.S. Publication No. 2005-0233380-A. In such aparticle production system, working gas is supplied from a gas source toa plasma reactor. Within the plasma reactor, energy is delivered to theworking gas, thereby creating a plasma. A variety of different means canbe employed to deliver this energy, including, but not limited to, DCcoupling, capacitive coupling, inductive coupling, and resonantcoupling. One or more material dispensing devices introduce at least onematerial, preferably in powder form, into the plasma reactor. Thecombination within the plasma reactor of the plasma and the material(s)introduced by the material dispensing device(s) forms a highly reactiveand energetic mixture, wherein the powder can be vaporized. This mixtureof vaporized powder moves through the plasma reactor in the flowdirection of the working gas. As it moves, the mixture cools andparticles are formed therein. The still-energetic output mixture,comprising hot gas and energetic particles, is emitted from the plasmareactor. Following emission from the plasma reactor, the output mixturecan cool further. This output mixture may comprise hot gas and particlesof relatively homogeneous size distribution. Each particle can comprisea combination of the materials introduced by the material dispensingdevices. It is contemplated that portions of these or other particleproduction means, including non-vapor phase particle production means,are within the scope of the present invention as well and can beemployed as part of the particle production core 120.

In a preferred embodiment, the reactor 122 is fluidly coupled to aworking gas supply 110 via a working gas inlet 111, thereby allowing thereactor 122 to receive a working gas from the working gas supply 110.Examples of working gas include, but are not limited to, argon andhydrogen. The reactor 122 can also be fluidly coupled to a precursormaterial supply 115 via a precursor material inlet 116, thereby allowingthe reactor 122 to receive precursor material, such as precursormaterial powder, from the precursor material supply 115. The reactor 122combines the working gas and the precursor material to produce areactive particle-gas mixture. In a preferred embodiment, as discussedabove, energy is delivered to the working gas within the reactor 122,thereby creating a plasma. The plasma is then applied to the precursormaterial. The application of the plasma to the precursor material(s)forms a highly reactive and energetic mixture, wherein the powder can bevaporized. This mixture of vaporized powder moves through the reactor122 in the flow direction of the working gas. This reactive particle-gasmixture flows into the quench chamber 124, preferably via reactivemixture port 123, which fluidly couples the reactor 122 to the quenchchamber 124.

In addition to being configured to receive the reactive mixture from thereactor 122, the quench chamber 124 is also configured to receiverecirculated conditioning fluid. One example of a conditioning fluid isargon. However, it is contemplated that other fluids may be used inaddition to or as alternatives to argon. In a preferred embodiment, thequench chamber 124 is housed within a conditioning fluid input manifold125, which itself receives recirculated conditioning fluid through aconditioning fluid inlet 119. The conditioning fluid is supplied to theconditioning fluid input manifold 125 via a recirculation systemdiscussed in detail below. The manifold 125 is fluidly coupled to thequench chamber 124, preferably via one or more conditioning fluid ports121, thereby providing the recirculated conditioning fluid to the quenchchamber 124.

The quench chamber 124 mixes the conditioning fluid with the reactiveparticle-gas mixture from the reactor 122, thereby quenching thereactive particle-gas mixture. This quenching rapidly cools the reactivemixture to form a cooled particle-gas mixture. The cooled mixture ispreferably drawn into a conduit system 126 that is fluidly coupled tothe quench chamber. In a preferred embodiment, the cooled mixture isdrawn into the conduit system 126 by suction supplied by a suctiongenerator 128, such as a pump, drawing the cooled mixture towards thesuction generator 128. A powder product can be sampled or collected fromthe cooled mixture between the quench chamber 124 and the suctiongenerator 128. Such sampling or collection can be achieved in a varietyof ways.

Outside of the quench chamber 124 and the particle production core 120,the rest of the particle production system 100 comprises a fluidrecirculation system, which includes a plurality of elements fluidlycoupled via a conduit system 180. The fluid recirculation system isconfigured to receive the cooled mixture from the particle productioncore, filter the cooled mixture to produce a filtered output, modulatethe content ratio of the filtered output to produce acontent-controlled, filtered output, and channel the content-controlled,filtered output to the particle production core 120 to be used as therecirculated conditioning fluid in quenching the reactive mixture. Themeans for performing these operations, as well as other functions, willbe discussed in further detail below.

In a preferred embodiment, the fluid recirculation system comprises afilter element 130 fluidly coupled to the suction generator, a pressurerelief module 140 fluidly coupled to the filter element 130, atemperature control module 150 fluidly coupled to the pressure reliefmodule 140, and a content ratio control module 160 fluidly coupled tothe temperature control module 150 and to the particle production core120, thereby creating a recirculation path from the output of theparticle production core 120 to the input of the particle productioncore 120. It is contemplated that the scope of the present invention caninclude the rearrangement or removal of some of these components. Forexample, pressure relief module 140 may be disposed between temperaturecontrol module 150 and content control module 160, rather than betweenfilter element 130 and temperature control module 150. In an alternativeexample, pressure relief module 140 can be completely removed from thefluid recirculation path.

The suction generator 128 preferably moves the cooled particle-gasmixture out of the particle production core through the conduit system126 and into the filter element 130. The filter element 130 isconfigured to remove remaining particles, such as precursor materialparticles, from the cooled mixture, thereby producing a filtered output.Preferably, the filter element 130 is a high efficiency particulate air(HEPA) filter. In some embodiments, the filter element 130 does notcompletely remove all of the particles from the cooled mixture.

Following passage through the filter element 130, the cooled mixturebecomes a filtered output, which is channeled into the conduit system180. The conduit system 180 fluidly couples the filter element 130 tothe pressure relief module 140 such that the pressure relief module 140can receive the filtered output from the filter element 130. Thepressure relief module 140 is configured to reduce the pressure of thefluid of the filtered output. This pressure reduction can be conditionedupon the pressure of the fluid exceeding a predetermined threshold.Furthermore, this pressure reduction can be achieved in a variety ofways, including, but not limited to, venting to ambient atmosphere. Asnoted above, in some embodiments, no pressure relief module 140 isincluded at all.

Following passage through the pressure relief module 140, the filteredoutput passes into the temperature control module 150. The temperaturecontrol module 150 is configured to regulate the temperature of theoutput, thereby forming a temperature-controlled, filtered output. In apreferred embodiment, the temperature control module 150 comprises aheat exchanger. Additionally, in some embodiments, no temperaturecontrol module 150 is included at all.

The temperature-controlled, filtered output reenters a portion of theconduit system 180 that fluidly couples the temperature control module150 to the content ratio control module 160. The content ratio controlmodule 160 is configured to receive and modulate the content ratio ofthe temperature-controlled, filtered output, thereby producing acontent-controlled, temperature-controlled, filtered output. In apreferred embodiment, the filtered output that is received by thecontent control module 160 comprises a distinct primary fluid and adistinct secondary fluid. The content control module 160 controls theratio of the primary fluid to the secondary fluid, making adjustmentswhen necessary, thereby producing the content-controlled output.

This content-controlled output, still comprising conditioning fluid fromthe quench chamber, is then channeled through another portion of theconduit system 180 to the conditioning fluid inlet 119 of the particleproduction core 120 for use in quenching. Thus, the output of the quenchchamber 124, which includes the conditioning fluid, has beenrecirculated back into the quench chamber 124. This recirculationincludes the filtering and the content control (and in some cases, thepressure relief and the temperature control) of the fluid to ensuresufficient preparation for the fluid's reuse in quenching the reactivemixture in the particle production core 120.

FIG. 2 illustrates one embodiment of a particle production system 200,similar to the system 100 of FIG. 1, with a more detailed embodiment ofthe content ratio control module 160 in accordance with the principlesof the present invention. The content ratio control module 160 caninclude a plurality of components. Some components are fluidly coupledwith the conduit system 180. For example, a buffer reservoir 260 ispreferably coupled to the conduit system 180 and in fluid communicationwith the temperature control module 150.

The content ratio control module 140 of some embodiments receives thetemperature-controlled, filtered output from the temperature controlmodule 150 in the buffer reservoir 260. The buffer reservoir 260 acts asa fluid buffer, holding the temperature-controlled, filtered output fora period of time before releasing it. During the time while thetemperature-controlled, filtered output is within the buffer reservoir260, the fluid within the output begins to separate based on densitybecause of gravity. In the embodiments where the output comprises aprimary fluid and a secondary fluid, the secondary fluid is preferably aless dense fluid. Thus, in these embodiments, the primary fluidconcentrates in a lower portion of the buffer reservoir 260, while thesecondary fluid concentrates in an upper portion of the buffer reservoir260.

In a preferred embodiment, the content control module also comprises acontent ratio sensor 262 coupled into the conduit system and in fluidcommunication with the buffer reservoir 260. The content ratio sensor262 is configured to receive a portion of the fluid mixture, determinethe content ratio of the mixture (e.g., the ratio of primary fluid tosecondary fluid), and provide one or more signals representing thecontent ratio.

The buffer reservoir 260 can be configured to permit venting of thesecondary fluid from the system 200. In one embodiment of such aconfiguration, the buffer reservoir 260 is fluidly coupled to asecondary fluid relief element 264. The secondary fluid relief element264 is in fluid communication with the ambient environment of theparticle production system 200 and is configured to selectively permitfluid communication between the buffer reservoir 260 and the ambientatmosphere.

A secondary fluid supply 266 can be fluidly coupled to the conduitsystem 180 to permit selective fluid communication with the conduitsystem 180, and thereby with the content ratio sensor 262. The secondaryfluid supply 266 is configured to store and selectively introduce anamount of secondary fluid into the fluid mixture to increase the amountof secondary fluid in the mixture relative to the amount of primaryfluid, thereby adjusting the content ratio.

The content ratio control module 160 preferably includes amicro-controller 268. The micro-controller 268 is communicativelyconnected to the content ratio sensor 262, thereby enabling themicro-controller 268 to receive signals from the content ratio sensor262 that represent the content ratio of the fluid within the conduitsystem 180 that is in the vicinity of the content ratio sensor 262. Themicro-controller 268 is also communicatively connected to the secondaryfluid supply 266 and the secondary fluid relief element 264, therebyenabling the micro-controller 268 to select whether the secondary fluidsupply 266 is in fluid communication with the conduit system 180 to addsecondary fluid and select whether the relief element 264 provides fluidcommunication between the buffer reservoir 260 and the ambientenvironment to vent the secondary fluid. The micro-controller 268 canmake any or all of these selections based on the content ratio asrepresented by the signal provided by the content ratio sensor 262.

During the time while the temperature-controlled, filtered output iswithin the buffer reservoir 260, the secondary fluid relief module 264can operate to make an initial adjustment to the level of secondaryfluid within the buffer reservoir 260. The relief module 264 ispreferably coupled to the upper portion of the buffer reservoir 260 totake advantage of the gravity-based separation of the secondary andprimary fluids. The micro-controller 268 controls relief of thesecondary fluid by the relief module 264. Preferably, the secondaryfluid relief module 264 operates by relieving fluid at a continuousrate. The rate can be variable and is preferably determined by themicro-controller 268.

Following the initial adjustment of the secondary fluid level, theadjusted output moves out of the buffer reservoir 260 and into a portionof the conduit system 180 that fluidly couples the buffer reservoir 260to the content ratio sensor 262. The content ratio sensor 262 detectsthe ratio of the primary fluid to the secondary fluid within theadjusted output, then sends a signal representing the ratio to themicro-controller 268.

Meanwhile, the adjusted output moves through another portion of theconduit system 180 that fluidly couples the sensor 262 to the outlet ofthe secondary fluid supply 266. The micro-controller 268 controls thesecondary fluid supply 266 to introduce secondary fluid into theadjusted output. The micro-controller 268 uses the signal from thecontent ratio sensor 262 in determining the rate at which secondaryfluid is introduced into the output. The result of these adjustments isthe production of a content-controlled, temperature-controlled, filteredoutput.

This output is channeled through a portion of the conduit system 180that fluidly couples the outlet of the secondary fluid supply 266 to theconditioning fluid inlet 119 of the particle production core 120. Thus,the content-controlled, temperature-controlled, filtered output issupplied to the particle production core 120 as conditioning fluid.

Because the working gas from the working gas supply 110 becomes part ofthe output of the particle production core 120, the recirculatedconditioning fluid comprises the working gas. In some embodiments, theconditioning fluid is initially supplied from the working gas supply 110in a charging step, where no precursor material is introduced into thereactor 122. The fluid recirculation system works during the chargingstep to modulate the characteristics of the conditioning fluid untildesired characteristics are reached, at which point, the precursormaterial is introduced into the reactor 122.

FIG. 3A is a schematic illustration of one embodiment of a content ratiocontrol module 300, similar to content ratio control module 160 shown inFIG. 2, in accordance with the principles of the present invention. Aportion of the content ratio control module 300 is disposed along theconduit system 180. The conduit system 180 provides fluid communicationbetween a buffer reservoir 260, a content ratio sensor 262, and asecondary fluid supply valve 366.

The secondary fluid supply valve 366 is fluidly coupled to a secondaryfluid reservoir 367. The secondary fluid supply reservoir 367 contains asecondary fluid G2. The supply valve 366 enables selective fluidcommunication between the secondary fluid reservoir 367 and the conduitsystem 180, thereby allowing for the introduction of additionalsecondary fluid G2 into the conduit system 180 when appropriate.

Similarly, a primary fluid supply valve 376 is fluidly coupled betweenthe buffer reservoir 260 and a primary fluid reservoir 377, whichcontains a primary fluid G1, thereby enabling selective fluidcommunication between the primary fluid reservoir 377 and the bufferreservoir 260 and allowing for the introduction of additional primaryfluid G1 into the conduit system 180 when appropriate.

Additionally, the buffer reservoir 260 can be fluidly coupled to asecondary fluid relief valve 364, which is fluidly coupled with theambient atmosphere, thereby enabling selective fluid communicationbetween the buffer reservoir 260 and the ambient atmosphere. In anexemplary embodiment, the buffer reservoir 260 contains both primaryfluid G1 and secondary fluid G2.

The content ratio control module 300 further includes micro-controller268. The micro-controller 268 is communicatively connected to thecontent ratio sensor 262, thereby enabling the micro-controller 268 toreceive signals from the content ratio sensor 262 that represent thecontent ratio of the fluid within the conduit system 180 that is in thevicinity of the content ratio sensor 262. The micro-controller 268 isalso communicatively connected to the secondary fluid supply valve 366,the secondary fluid relief valve 364, and the primary fluid supply valve376, thereby enabling the micro-controller 268 to select whether thesecondary fluid supply reservoir 367 is in fluid communication with theconduit system 180 to add secondary fluid, to select whether thesecondary fluid relief valve 364 provides fluid communication betweenthe buffer reservoir 260 and the ambient environment to vent thesecondary fluid, and to select whether the primary fluid supplyreservoir 377 is in fluid communication with the conduit system 180 toadd primary fluid. The micro-controller 268 can make any or all of theseselections based on the content ratio as represented by the signalprovided by the content ratio sensor 262.

In operation, the content ratio control module 300 receives thetemperature-controlled, filtered output in the buffer reservoir 260. Thebuffer reservoir 260 acts as a fluid buffer, holding thetemperature-controlled, filtered output for a period of time beforereleasing it.

During the time while the temperature-controlled, filtered output iswithin the buffer reservoir 260, the fluid within the output begins toseparate based on density because of gravity. In the embodiments wherethe output comprises a primary fluid G1 and a secondary fluid G2, thesecondary fluid G2 is preferably a less dense fluid. Thus, in theseembodiments, the primary fluid G1 concentrates in a lower portion of thebuffer reservoir 260, while the secondary fluid G2 concentrates in anupper portion of the buffer reservoir 260.

Also, during the time while the temperature-controlled, filtered outputis within the buffer reservoir 260, the secondary fluid relief valve 364can operate to make an initial adjustment to the level of secondaryfluid G2 within the buffer reservoir 260. The relief valve 364 ispreferably coupled to the upper portion of the buffer reservoir 260 totake advantage of the gravity-based separation of the secondary fluid G2and primary fluid G1. The micro-controller 268 controls relief of thesecondary fluid G2 by the relief valve 364. Preferably, the secondaryfluid relief valve 364 operates by relieving secondary fluid G2 at acontinuous rate. The rate can be variable and is preferably determinedby the controller 268.

Additionally, during the time while the temperature-controlled, filteredoutput is within the buffer reservoir 260, the primary fluid supplyvalve 376 and reservoir 377 can operate to make an initial adjustment tothe level of primary fluid G1 within the buffer reservoir 260. Althoughnot shown, the primary fluid supply valve 376 can be coupled to thelower portion of the buffer reservoir to take advantage of thegravity-based separation of the secondary fluid G2 and primary fluid G1.The micro-controller 268 controls supply of the primary fluid G1 by thevalve 376. Preferably, the primary fluid supply valve 376 operates bysupplying primary fluid G1 at a continuous rate. The rate can bevariable and is preferably determined by the micro-controller 268.

Following the initial adjustment of the secondary fluid level, theadjusted output moves out of the buffer reservoir 260 and into a portionof the conduit system 180 that fluidly couples the buffer reservoir 260to the content ratio sensor 262. The content ratio sensor 262 detectsthe ratio of the primary fluid G1 to the secondary fluid G2 within theadjusted output and sends a signal representing the ratio to themicro-controller 268.

Meanwhile, the adjusted output moves through another portion of theconduit system 180 that fluidly couples the sensor 262 to the secondaryfluid supply valve 367. The micro-controller 268 controls the secondaryfluid supply valve 3672 to selectively introduce secondary fluid G2 intothe adjusted output from the secondary fluid reservoir 367. Themicro-controller uses the signal from the content ratio sensor 262 indetermining the rate at which secondary fluid G2 is introduced into theoutput. The result of these adjustments is the production of acontent-controlled, temperature-controlled, filtered output.

This output is channeled through a portion of the conduit system 180that fluidly couples the content ratio control module 300 to theconditioning fluid inlet of the particle production core 120. Thus, thecontent-controlled, temperature-controlled, filtered output is suppliedto the particle production core 120 as conditioning fluid.

FIG. 3B is a schematic illustration of another embodiment of a contentratio control module 300′ in accordance with the principles of thepresent invention. Content ratio control module 300′ is the same ascontent ratio control module 300, except that module 300′ does notinclude primary fluid supply valve 376 or primary fluid supply reservoir377. In an alternative embodiment, primary fluid supply valve 376 andprimary fluid supply reservoir 377 can be present while secondary fluidsupply valve 366 or secondary fluid supply reservoir 367 are excluded.It is contemplated that several other different configurations are alsowell within the scope of the present invention.

FIG. 4 is a flow chart illustrating one embodiment of a method ofrecirculating a fluid in a particle production system in accordance withthe principles of the present invention.

At step 402, the particle production core performs two main functions.First, it produces a reactive particle-gas mixture using a working gasand a precursor material. Preferably, this operation is performed via aparticle production reactor as discussed above. Second, the particleproduction core quenches the reactive particle-gas mixture usingrecirculated conditioning fluid, resulting in the production of a cooledparticle-gas mixture, which comprises a plurality of precursor materialparticles. Preferably, this operation is performed via a quenchingchamber as discussed above.

The cooled particle-gas mixture then flows out of the particleproduction core and into the fluid recirculation system for preparationbefore being re-introduced back into the particle production core foruse in quenching.

At step 404, the cooled particle-gas mixture flows into a filter, wherethe filter removes the precursor material particles from the cooledparticle-gas mixture, thereby producing a filtered output. It iscontemplated that, in some embodiments, the filter can be configured toremove all of the precursor material particles in the cooledparticle-gas mixture, leaving no precursor material particles in thefiltered output, while in other embodiments, the filter can beconfigured to remove less than all of the precursor material particlesin the cooled particle-gas mixture, leaving a certain amount of theprecursor material particles remaining in the filtered output.

At this point, the filtered output flows to the content ratio controlmodule. However, it is contemplated that the filtered output canoptionally be subjected to additional preparation before reaching thecontent ratio control module. If this additional preparation is desired,then at step 405, the filtered output can undergo temperature controland/or pressure relief, as discussed above with respect to thetemperature module and the pressure relief module. For example, aportion of the filtered output can be vented to ambient, therebyreducing the pressure of the filtered output. The filtered output canthen flow through a heat exchanger, thereby reducing its temperature.

At step 406, the filtered (and possibly temperature-controlled andpressure-relieved) output reaches the content ratio control module,where its content ratio is modulated. In a preferred embodiment, thefiltered output comprises a distinct primary fluid and a distinctsecondary fluid, and the content ratio is the ratio of the primary fluidto the secondary fluid. As discussed above, this modulation of thecontent ratio can involve one or more operations, including, but notlimited to, a decrease in the amount of a certain fluid or the increasein the amount of a certain fluid. These operations are preferablyperformed with the use of one or more components, such as themicro-controller, sensor, reservoirs, and valves discussed above. Theresult of this content ratio modulation is the production of acontent-controlled, filtered output that is now acceptable for reuse asconditioning fluid in quenching the reactive particle-gas mixture backin the particle production core.

At step 408, a channeling element recirculates the content-controlled,filtered output into the particle production core for use asconditioning fluid in the quenching of the reactive mixture back at step402. This process 400 can be repeated several times, wherein the sameconditioning fluid is recirculated and reused over and over again.

Embodiments of the present invention permit the recirculation and reuseof conditioning fluids within a particle production system. Furthermore,these embodiments permit the adjustment of a content ratio of theconditioning fluids, which may otherwise change undesirably with systemuse. Particle production systems incorporating embodiments of thepresent invention do not need a constant supply of fresh conditioningfluid. When fresh fluid is supplied, the system uses it for multipleproduction runs. Since the cost of fresh conditioning fluid is spreadover more than one production run, the unit cost of the particlesproduced using the present invention is less than with conventionalmeans.

Additionally, some embodiments described herein permit recirculationusing filters with a specified tolerance so as not to filter out everyparticle from the output. These embodiments allow for use of lessexpensive filters on dedicated production lines wherecross-contamination is not an issue.

The present invention has been described in terms of specificembodiments incorporating details to facilitate the understanding of theprinciples of construction and operation of the invention. As such,references herein to specific embodiments and details thereof are notintended to limit the scope of the claims appended hereto. It will beapparent to those skilled in the art that modifications can be made tothe embodiments chosen for illustration without departing from thespirit and scope of the invention.

What is claimed is:
 1. A method of recirculating a fluid in a particleproduction system, the method comprising: producing a reactiveparticle-gas mixture from a precursor material and a working gas in aparticle production reactor; receiving a conditioning fluid at a fluidinlet of a quench chamber and receiving the reactive particle-gasmixture from the particle production reactor at a reactive mixture inletof the quench chamber; mixing the conditioning fluid with the reactiveparticle-gas mixture in the quench chamber, thereby producing a cooledparticle-gas mixture, the cooled particle-gas mixture comprising aplurality of precursor material particles and an output fluid, theoutput fluid including the conditioning fluid; receiving and filteringthe output fluid from the quench chamber using a filter element, therebyproducing a filtered output; receiving and controlling the temperatureof the filtered output using a temperature control module, therebyproducing a temperature-controlled, filtered output; receiving andmodulating a content ratio of the temperature-controlled, filteredoutput using a content ratio control module, thereby producing acontent-controlled, temperature-controlled, filtered output, wherein thetemperature-controlled, filtered output comprises a distinct primaryfluid and a distinct secondary fluid, and the content ratio is the ratioof the primary fluid to the secondary fluid; and supplying thecontent-controlled, temperature-controlled, filtered output to the fluidinlet of the quench chamber using a channeling element, wherein thecontent-controlled, filtered output is provided to the quench chamber asthe conditioning fluid to be used in quenching the reactive particle-gasmixture.
 2. The method of claim 1, wherein producing a reactiveparticle-gas mixture comprises: energizing the working gas to form aplasma; and applying the plasma to the precursor material, therebyproducing the reactive particle-gas mixture.
 3. The method of claim 1,further comprising generating a suction force at the cooled mixtureoutlet of the quench chamber to draw the output fluid from the quenchchamber using a suction generator.
 4. The method of claim 1, wherein thefilter element removes the plurality of precursor material particlesfrom the output fluid to produce the filtered output.
 5. The method ofclaim 4, wherein the filter element comprises a high efficiencyparticulate air (HEPA) filter.
 6. The method of claim 1, furthercomprising reducing the pressure of the filtered output if the pressureexceeds a predetermined threshold using a pressure relief module.
 7. Themethod of claim 1, wherein the temperature control module comprises aheat exchanger.
 8. The method of claim 1, wherein modulating the contentratio comprises: sensing the content ratio of thetemperature-controlled, filtered output using a sensor; producing asignal representing the sensed content ratio; receiving the signal fromthe sensor at a micro controller; and modulating the content ratio ofthe content-controlled, temperature-controlled, filtered output that isto be supplied to the fluid inlet of the quench chamber based on thereceived signal using the micro controller.
 9. The method of claim 8,further comprising: receiving the temperature-controlled, filteredoutput from the temperature control module at a buffer reservoir; andtemporarily storing the temperature-controlled, filtered output in thebuffer reservoir before the content ratio of the temperature-controlled,filtered output is modulated.
 10. The method of claim 9, wherein themodulating the content ratio further comprises venting the secondaryfluid from the buffer reservoir to the ambient atmosphere using a fluidrelief valve.
 11. The method of claim 9, wherein modulating the contentratio further comprises: storing a supply of the secondary fluid in asecondary fluid supply reservoir; and selectively adding a portion ofthe secondary fluid from the secondary fluid supply reservoir into thetemperature-controlled, filtered output in response to a signal from themicro-controller using a secondary fluid supply valve, thereby producingthe content-controlled, temperature-controlled, filtered output.
 12. Themethod of claim 11, wherein modulating the content ratio furthercomprises: storing a supply of the primary fluid in a primary fluidsupply reservoir; and selectively adding a portion of the primary fluidfrom the primary fluid supply reservoir into the temperature-controlled,filtered output using a primary fluid supply valve in response to asignal from the micro-controller, thereby producing thecontent-controlled, temperature-controlled, filtered output.
 13. Amethod of recirculating a fluid in a particle production system, themethod comprising: producing a reactive particle-gas mixture from aprecursor material and a working gas; mixing a conditioning fluid withthe reactive particle-gas mixture in a quench chamber to produce acooled particle-gas mixture, the cooled particle-gas mixture comprisinga plurality of precursor material particles and an output fluid, theoutput fluid including the conditioning fluid; filtering the outputfluid to produce a filtered output; controlling the temperature of thefiltered output to produce a temperature-controlled, filtered output;modulating a content ratio of the temperature-controlled, filteredoutput to produce a content-controlled, temperature-controlled, filteredoutput, wherein the temperature-controlled, filtered output comprises adistinct primary fluid and a distinct secondary fluid, and the contentratio is the ratio of the primary fluid to the secondary fluid; andsupplying the content-controlled, temperature-controlled, filteredoutput to a fluid inlet of the quench chamber, wherein thecontent-controlled, filtered output is provided to the quench chamber asthe conditioning fluid to be used in quenching the reactive particle-gasmixture.
 14. The method of claim 13, wherein producing a reactiveparticle-gas mixture comprises: energizing the working gas to form aplasma; and applying the plasma to the precursor material to produce thereactive particle-gas mixture.
 15. The method of claim 13, furthercomprising generating a suction force at the cooled mixture outlet ofthe quench chamber to draw the output fluid from the quench chamber. 16.The method of claim 13, wherein filtering the output comprises removingthe plurality of precursor material particles from the output fluid. 17.The method of claim 13, further comprising reducing the pressure of thefiltered output if the pressure exceeds a predetermined threshold. 18.The method of claim 13, wherein modulating the content ratio comprises:sensing the content ratio of the temperature-controlled, filteredoutput; producing a signal representing the sensed content ratio;modulating the content ratio of the content-controlled,temperature-controlled, filtered output that is to be supplied to thefluid inlet of the quench chamber based on the content ratio of thetemperature-controlled, filtered output.
 19. The method of claim 18,further comprising: receiving the temperature-controlled, filteredoutput from the temperature control module at a buffer reservoir; andtemporarily storing the temperature-controlled, filtered output in thebuffer reservoir before the content ratio of the temperature-controlled,filtered output is modulated.
 20. The method of claim 19, whereinmodulating the content ratio further comprises venting the secondaryfluid from the buffer reservoir to the ambient atmosphere.
 21. Themethod of claim 19, wherein modulating the content ratio furthercomprises: storing a supply of the secondary fluid in a secondary fluidsupply reservoir; and selectively adding a portion of the secondaryfluid from the secondary fluid supply reservoir into thetemperature-controlled, filtered output.
 22. The method of claim 21,wherein modulating the content ratio further comprises: storing a supplyof the primary fluid in a primary fluid supply reservoir; andselectively adding a portion of the primary fluid from the primary fluidsupply reservoir into the temperature-controlled, filtered output.